Best that i can tell, there's a Black man on square 3 (not a King) so the boy must be playing the Black side. I don't see any White men on the board and the girl looks so happy. So maybe she has just won a game of Suicide Checkers.

Liam, thanks for posting this vintage magazine cover. I have not seen this before! That is very good attention to detail by the artist Sambrook; the artist knows his checkers!Of course, the year 1928 places it in the era of the Great Gonotsky!